Bomb-throwing device for aircraft



May 15, 1923.

O. AWILCKE BOMB THROWING DEVICE FOR AIRCRAFT 4 Sheets-Sheet 1 Filed ,June 28 1920 INVENTOR2 6 May 15, 1923. 1,454,990

0. WILCKE v BOMB THROWING DEVICE FOR AIRCRAFT Filed June 28, 1920 4. Sheets- Sheet 2 INVENTORZ 0. WILCKE BOMB THROWING DEVICE FOR AIRCRAFT Filed June 28, 1920 4 Sheets-Sheet 3 L "l ln 2;

o. WILCKE BOMB THROWING DEVICE FOR AIRCRAFT 4 Sheets-Shet 4 Filed June 28, 1920 figs a INVENTORI Patented May 15, 1923.

UNITED STATES.

I v 1,454,990 PATENT OFFICE.

oso'aa WILCKE, or raIa'inuonsnarinv, onamNY,..AssIonon TO THE rum: Lumsonrrrzeau zarrrmm GESELLSCHAFT m'r BESCHRANKTER neurone, or ramp- RICESEAFEN, GERMANY.

-BOMB-THROWING DEVICE FOR AIRCRAFT.

Application filed June 28,1920. Serial No. 392,578.

To all whom it may concern:

Be it known that I, OSCAR WILCKE, a German citizen, residing at Friedrichshafen,

. Germany, have invented certain new anduseful Improvements in Bomb-Throwing Devices for Aircraft '(for whichI have filed application in Germany September 13, 1915, Patent No. 315,110, and February 4, 1916, Patent No. 316,786), of which the following 10 is a specification.

My invention relates to a bomb-throwing device for aircraft, and purposes to successfully solve the problem of enabling a large number of bombs to be thrown off from an aircraft either singly, in succession, or in groups of any desired number, and that in any desired Order by an electromagnetic release oftheir suspension means. This object is to be accom lished with complete reliability as regar s the dropping of the bombs, along with clearness of arrangement, and convenient manipulation of the single witch devices.

The object is chiefly attained, in accordance with my present invention, by the fact that the e'lectromagnets, acting on the suspension means for the single bombs, may be connected with the source of current both by means of a distributor, adapted to supply them successively'with current, as also with shunt branches, which may be rendered active in any number and any order of succession desired by the closing of switches, the distributor serving to drop single bombs,

' while by switching in the shunt branches,

entire groups of bombs may be thrown of simultaneously. Moreover, by means of a system of plugs, the possibility is afforded of the a distributor also dropping single bombs regardless of the true order of succession in which they are suspended.

The simultaneous actuation of a group of shunt branches may be efiected by means of a special group switch directly connecting the joint conductor, with which all the shunts proceeding from the electromagnets communicate, with the source of current. However, even this group switch may be replaced by the distributor by the jointconductor, to which the parallelly disposed branch shunts are connected, being fed by the respective shunt branch belonging to the distributor contact switched in forthe time being.

Preferably a lamp circuit is branched oif fro'mthe circuit of each electromagnet, and which is controlled by means of a contact, arranged at the suspension device for the bombs, in such a manner that while the bomb is hanging on its hook it will be closed, to be opened the instant the bomb drops. Thus the burning of the indicator lamp denotes that the bomb is hanginglin its place, and the moment it is extinguis ed that the bomb has dropped.

. A further feature of this invention resides in the provision of means intended to obviate a deficiency connected with the action of the distributor.

In the form of connection hitherto known, all the contacts belonging to a distributor must be opened while it is in a position of rest, since, in the contrary event, the current would always be switched on to one of the electromagnets, even when no bombs were to be v dropped, and the battery serving as the source of current would speedily be spent. Hence, the contact of the electromagnet about. tobe excited is only closed during the switching motion, and must be re-opened when this motion has been completed. However, the impulse lent to the movable part of the distributor will not, under all circumstances, be so damped as to allow the distributor contact to establish a suificiently long contact in order to obtain the time required for exciting the electromagnet and accelerating the electromagnetlc armature loaded by lever press'ure. If the movable portion of the distributor, consist of a switch lever which may be shifted by hand across the stationary contacts, then the inertia appertaining to the human hand may easily cause thecontacts being too quickly crossed. If, on the other hand, the movable part of the distributor consist of a contact roller or a contactdisc, which is turned stepwise by means of a switch lever and a switch hand wheel, then again, owing to the inertia of the masses moved, the contact may again be crossed at too great a speed. Thus it may ha pen in connection with the arrangement escribed, that notwithstanding the distributor lever. respec-. tively, the switch lever, having T. sen properly manipulated, the bomb will failto drop.

This drawback is obviated by a drag s itch, say, one a kmfe switch,

being actuated contemporaneously with the stepwise rotation of the movable distributor member (contact roller or disc) into the contact position re uired for the time being; the said drag switc or other being disposed in series with the distributor contact. By these means, the duration of the current closing period is adequately extended, since the motion of the distributor lever, or of the lever supporting the knife being retarded by the drag contact. Now this retardation will already suflice for the case so far considered, namely of the distributor contact being open when in the state of rest, and closed during the switching operation. The interconnection of the drag contact, however, in addition affords the possibility of the distributing contacts being always closed when the distributor is in a state of rest, for the current is only switched in as long as the drag contact is switched in, so that the distributor coming to a standstill while the contact is closed will have no injurious effect. It thus results that in this improved arrangement the entire period of closing the drag contact is utilized for the purpose of feeding the electromagnet, so that there is provided ample security for the contact lasting as long as required. A special advantage will be obtained by the series connection of this said drag contact over and above the arrange ment of single branch currents in the case of airships. To safeguard against an ignition of the gas carrying the airship, all the contacts, where spark formation is liable to arise, must be kept in a spark-proof oil cage. Such a requirement naturally involves the necessity of rendering the structure considerably more intricate. If, on the other hand, the drag contact connected to the distributor contacts be so arranged that the switching from one distributor contact on to the next will already be completed before the drag contact shuts the current, then the operation of changing contacts at the distributor Will be effected in the absence of current. The only possibility for the formation of sparks prevails at the drag contact while it is being either opened or closed. For this reason it will suffice if only the drag contact be placed in an oil cage, so that by the interconnection of the said contact the structure of the switch arrangement will be substantially simplified and cheapened.

Various embodiments of the subject matter of my invention are shown by way of example in the accompanying drawings, in which:

Figs. 1 to 3 illustrate various switch diagrams,

Figs. 4, 5 and 6 a switch device with contact roller,

Fig. 7 a stopping device,

Figs. 8 to 10 illustrate a modified form switch arrangement.

In all these cases the number of bombs entering into consideration is assumed to be, say, for example, twelve, though it is obvious that their number will be far greater in the majority of airships and fighting aircraft.

In the arrangement shown in Fig. 1, the battery a is connected with the network by a switch I). At the point a the line branches ofi, one branch running into the arm at of the distributor, adapted to be moved across the contacts 6,, e 6 etc. Connected withthese said contacts, are electromagnetic coils f f f which on the other hand are connected to a mass acting as the joint return conductor. At the-point 0 there is interconnected a line 1, into which a switch g is disposed. The parallelly arranged shunt branches fil it? h from the line Z to the mains disposed intermediate the distributor contacts and the electromagnetic coils; each of the said branches 71,, k 71- embodying a switch s s s The armature i is arranged opposite to the iron core of the elcctromagnetic coil f,, on which armature a lever is is arranged to rest, which in its turn supports the lever n on which the bomb on is suspended. Intermediate the distributor contacts and the electromagnetic coils there are interposed plug contacts 0 0 0 the plugs being connected with line cables 79 12 p in the proximity of the distributor contacts.

If it be desired to drop the bombs successively by means of this improved arrangement, then .the main switch I) is closed and the arm 03 of the distributor is moved successively across the single contacts e e e so that, if the plugs 0 have been inserted, the current will flow from the battery across the point 0 and the distributor contacts into the single electromagnetic windings and thence across the mass back to the battery. It will thus be seen that the electromagnets attract the armatures i in succession, so that the lever will be deprived of its points of support; as a result the weight of the bomb,will cause the lever system n, k, to tilt, and the bomb will drop off. Again, if it be not desired to throw off the bombs in accordance with the numerical succession in which they are hung up,.but at random and successively, then, this object may be attained by merely changing over the plugs. Thus, if, for example, bombs No. '3, No. 6 and No. 11 are to be thrown off, while the indicator, which denotes the position of distributor, shows that the distributing arm is at this instant standing on. No. 7 then all the plugs are removed, and the plug belonging to the distributor contact No. 8 is inserted in contact No. 3, that belonging to distributor contact No. 9 in No. 6, and the plug belonging to distributor contact No. 10 on to contact No.

Ill)

' ofi one of each set notwithstanding the distributor arm was enabled to merely shut the adjoining contacts Nos. 8, 9 and 10, will have been accomplished.

If, on the other hand, it be desired to throw off simultaneously a plurality of bombs, this may be done by aid of the shunt branches h. To this end,.those switches of the shunt branches are first closed which appertain to the bombs about to be thrown off, whereupon the group switch 9 is closed. Thus if, for example, the group comprisin bombs Nos. 2, 5, 8, 10 is to be thrown o then, after the group switch 9 has been closed, the electromagnet f f f and f will be excited and the respective bombs will accordingly drop.

The form of execution disclosed in Fig. 2 merely differs from that subject to Fig. 1 by the fact of all the shunt branches, which are parallelly disposed among themselves, being divided -into two parallel groups. The shunt branches k -h, are con nected with the conductor Z by intervention of their switches s, to 8,; the groups It, to k with the conductor l by aid of their switches 8, to 8 Each of the branches Z, and Z is controlled by a special group switch 9, and 9 respectively. At the same time always two switches of both groups are so disposed opposite to each other that they may be conveniently actuated by a common switch member. In the construction of the device as a knife contact (Fig. 2), a common knife thus serves to establish connection between the two oppositely disposed knife edges, in that said knife is shifted out of a central zero position either upward or downward. It will'generally prove most expedient to suspend the one group of bombs on the right hand side and the other on the left hand side of the. aircraft, and if, therefore after suitably setting the respective knife contacts, any desired number of shunt circuits be closed, then simply actuating the respective group switch will sufiice to throw off the entire group.- It is understood that the shunt branches might in this way be also divided into a plurality of parallelly disposed groups.

The construction disclosed in Fig. 3 distinguishes itself from that according to Fig.

1, by the feature of the common conductor, fromwhich the parallelly disposed shunt lines are arranged tobr'anch off, not being directly connected with the battery, butbeing merely; connected through the shunt branches themselves with the lines disposed intermediate the distributor contacts and the electroma ets. Hence, the current is supplied to al the shunt branches through that particular shunt branch which happens to be located at the distributor-contact. just closed. Thus, for instance, assuming a group of bombs are "to be thrown off simultaneously, the distributor in its position 'of rest be disposed intermediate the contacts 6 and e then the shunt switch 8 thereupon the shunt switches of the bomb group about to be thrown-off, say, 8, tos is closed, and

the switching of the'distributor ontinued in the ordinary manner. As soon as the distributor has closed the contact e the current flows from the batte across the distributor contact a throug branch I1, into the conductor h, whence 1t passes through the four parallel branches k, to h, to the respective electromagnets s, to 8,, so that the group'of bombs Nos.'1 to the shunt 4 will drop off. At the same time, however, I

bomb No. 8 will of course also drop ofi' because the distributor in the course of its motion closes the direct branch of the electromagnet f,. In the event of it not being desired that the bomb appertaining to the distributor contact drop off along with the group, then the roup switching arrangement indicated w1th respect to the arrangements disclosed in Figs. 1 and 2 must be employed, in which the distributor is'entirely dispensed with. However, here again the form of execution shown in Fig. 3 embodies the advantage of no special group switch 9 being required in that it is replaced by the distributor and that, by the interconnection of a main contact (drag contact), also the shunt switches will operate without emitting any sparks. y

In Fig. 3 there is in, addition shown the indicator lamp system. From the main line there is branched off a line 1', from which. I

again run the conductors r r '1', which are conducted across a spring contact 1,, t. t, to common conductor a.

By means of a push button switch a the lamp circuit may be temporarily connected with the source of current.- Within each of the lighting mains 7-,, r, 1', which are disposed in, parallel, there is lodged a small incandescent lamp to 20,, 10 2, 2, 2, o'f the-intermediate levers is, when the bomb is suspended in its place,

force the spring contacts t t,, t, against stationary contact bloc-ks so that the respective lamp current branches will be closed. Hence, when the bomb is hanging in place, the lamps w burn, provided the lighting switch '0 be closed. However, as soon as the system of levers appertaining to the suspension means be'released, and the levers k tilt over, thestops z causethe lam contacts t to open, so that the extinction of The stops in and at a switch box arranged at the air pilots stand, the magnets, serving to effect the release and therewith the dropping of the bombs, are disposed at a point of the frame of the aircraft remote from the switch box, while the mains leading to the electromagnets and to the lamps run along the P craft in parallel to each other. In the event of the aircraft suddenly getting into the midst of the enemys fire, there is the danger of the one or the other of these lines being destroyed by shot. This would entail the double drawback that the bomb throwing device may be rendered useless and that;

short circuit sparks will be created in consequence. of which the gas-filled airship might be blown up. To obviate these drawbacks, each oi-the electromagnet mains, as also each of the lighting mains is provided both at the switchbox as also close to the electromagnets with a plug switch. If now a magnet main happen to be suddenly destroyed use is immediately made of an adjoining lighting line for the purpose of in any case supplying the bomb-throwing device with current. It will be obvious that in such an extremity the operation of the indicator lamp belonging to this particular lighting line will be dispensed with. Thus, say, the electromagnet main 8 has been destroyed by fire from the enemy, while the lighting main 8 has remained intact, then plugs 36, 37, 38, 39 will be removed from these two lines, plug 36 being then inserted .in contact 37. and plug 38 in contact 39, so

that the current will now flow from the distributor contact e, across the plug contact 37, through the lighting main 1', and across the plug contact 39 into the electromagnet f For the purpose of ascertaining when a short circuit has arisen at the electromagnet coils, and thus to prevent the possibility of a gas explosion, there is arranged within the circuit of the shunt branches an ohm meter 40, adapted to be connected by means ot' the shunt switches with each of the single electromagnet coils. A potential resistance reduces the voltage to the degree required for the instrument. The ohmmeter is switched in by means ofa double ush button 43. 'Thestandard resistance the electromagnet coils is indicated on the calibration. If this resistance is not attained then there exists ashort circuit. In parallel to the ohm-meter there is arranged a comparison resistance 44 adapted to be put in b means of a switch 45. This resistance a fords the possibility of measuring at the same time the voltage. For should the source of current have sunk substantially below the standard voltage, then the ohmmeter will indicate the resistance of the coil to be higher than it actually is. If now the comparison resistance be switched in, which possesses exactly the same resistance .as the electromagnet coils, and if it be discovered that the deviation is the same for the comparison resistance as for the electromagnet coil, then it will have to be understood that the electromagnet coil is in order and that the deviation indicated on the measuring instrument is due to the varying voltage.

Figs. 4, and 6 indicate a form of execution for the distributor, in which the gradual rotation of the movable distributor section is effected by means of a switch lever. By depressing the switch lever once, the distributor disc is always rotated forward for a spansufiicient to secure the closing of a contact. An arrangement of this kind will prevent far better than an ordinary rotatable distributor arm the liability of a number of contacts being touched in qu ck succession. What is more, such a switch device, in the case of which the switch lever for each connection is struck in the manner of a piano key, may even be properly manipulated when the hand of the operator has become numbed by cold or been wounded.

The contact roller 10, which consists of an insulating material. is rotatably lodged in its pivots 11, 12. This roller supports the contact pins d d d d all of which are electrically connected with the pivot 1 1. say, by means of a wire 13 and the metal layer 14 of the roller. By means of an 1nsulating disc 15, the pivot 12 is electrically insulated from the contact pins and their connection. Within the circle of each contact pin there is arranged a stationary contact snap e e 6,, a These snap contacts are insulated the one from the other by being mounted on a block 16, composed of an insulating mater al. The switch wheel 17 is fixed to the roller. said wheel being driven by the pawl 18. The switch lever 19 which is adapted to freely rotate about the pivot .12. and which supports the pawls, is provided with a pan 20. in which the stern 21 of the switch handle 22 may lodge. sprng 23 draws the switch lever 19 and the handle 22 into their position of rest. A. contact bridge 24 is moreover fixed to the switch lever19, so as to be completely insulated, a'nd,which' faces-the two insulatingly disposed springs 25, 26 of a knife contact. This bridge will only then enter into engagement, on the switch handle being depressed, with the springs 25, 26, when the switch motion of the roller has so far progressed that the new distributorcontact will be closed. A spark can therefore only arise at the knife contact, and this latter,

to prevent the emiss'on of sparks in the case of airships, is disposed within an oilcage. The bombs are suspended on the hooks of the levers n, which with the intervention of the intermediate levers k, are disposed-on the armatures z of the electromagnets f. The electromagnet windings are disposed at the mass on the one hand by means of the snaps e e,, e, on the other by aid of the conductors 3 3 3 while the negative pole of the battery is disposed at the mass, the positive pole is connected by the conductor 27 with the spring 26 of' the knife contact. The other spring 25 of the knife contact is connected by a wire 28 with a sliding carbon 29, bearing ldown on the pivot 11.

e operation of the device is as follows: On the handle 22 being touched, the switch wheel 17 is moved forward for the space of a tooth by the pawl 18, and the contact pin 01 disengages the snap e while the contact pin d glides below the respective snap e retaining contact with this snap even after the switch motion has terminated.

After the contact pin 01,, has entered into contact with the snap 6 the bridge 24 comes to be disposed between the springs 25, 26 of the knife contact. Owing'to the clamping action which these springs exert on the con tact bridge, the depressing of the handle 22 comes to be retarded, and even when the handle has been released and after the rotation of the'switch roller has terminated, the spring 23 again requires a certain amount of time before it is able to withdraw the bridge 24 from the knife contact, and to set the pawl 18 on to the next tooth. The current, which flows from the positive pole of the battery across the spring 26, the bridge 24, the spring 25 of the knife contact into the contact carbon 29, and across the pivots 11 and the pin d of the contact roller and the snap 6 to the electromagnet f and thence across the conductor g and the mass back to the negative pole of the battery, thus has ample time to excite the'electromagnet f and to attract the armature z',-so that the bomb willbe sure to be thrown off.

To prevent the roller, owing to the inertia of the agitated mass,- from shooting beyond the contact, there is provided an arresting device similar to the esca ements arranged in clock-works (Fig. 7-). he pin carrying disc 30 is firmly connected w ththe roller 10, while the switch lever 19, effects the movement of a tooth 31. This latter, as it rotates, depresses a bevelled lug 32, in consequence of which the escapement 33 is raised out of the disc 30 before the lost motion of the switch gear has been balanced. After the switch motion has been completed, the tooth 31 allows the lug 32 to resume its former position so that the escapement 33 will bear up against the neirt locking pin. A resilient stay wedge 34 serves to secure the eugcit displacement for, the space of a tooth p1 c r o In the place of the simple suspension of the bombs on levers, as hereinbefore set forth, use may also be made'of a lever system which will automatically return into the supporting position required for suspending a fresh bomb.

In the case of fighting aeroplanes, the number of the bombs carried on board will be very big, say, about 120. For such a-contingency the device serving to throw off the bombs is first of all provided with a contact roller, adapted to be gradually fed forward by means of a depressible switch lever, in the manner of the arrangement shown in 90 Figs. 4 and 5. A second device provided for such aircraft, consists in a distributor,

the movable half of which is rotated without intermission by means of a crank to enable the bombs to be thrown ofi" rapidly in quick succession. However, to prevent the contacts from being operated too rapidly, and thus to avoid the possibility, which would result inevitably herefrom, of certain of the bombs not being released, i. e., dropped, there is interconnected between the hand crank and the rotating contact member a gearing, and this in such wise that three revolutions of the hand crank would have to be effected in order to once rotate the distributor drum.

In the case of the bomb-throwing device hereinbefore described, there is arranged at the air-pilots stand a switch box containing the various switch levers, the measuring instrument, the indicator lamps, the insulating test instrument, etc. As the indicator lamps are controlled by means of a contact by the lever systems supporting the bombs, the lighting mains are naturally con- 11 ducted from the switch box, in which the lamps and the lighting switches are contained, to the throw-off standards, and thence back to the battery. It thus follows that the lighting-mains, likethe mains of the 'electromagnets, constitute long outer mains in particular in the case of big aircraft, such as airships. Now this not only embodies a considerable consumption of conducting material, but furthermore the liabil- 12 ity ofshort circuits.

This drawback may be obviated in accordance with a special feature of the present 1nvention by the lighting main being so arranged that it will not directly bridge the throw-ofl? switch of .the electromagnet mains,

.and by the control contact disposed at the throw-ofi standard not being arranged in the lighting main but in the main of the electromagnet. This will give the result that one long outer main will now sufiice in the place of two. And in addition thereis obtained the advantage of obviating the possibility of a needless consumption of current, such as might be apt to arise if by mistake the electromagnet main were kept closed, by the control contact being adapted to open automatically.

The arrangement may be still further improved by merely interposing in the main bridging the throw-off switch, the coil of a relay controlling the circuit which contains the indicator lamp put in the direct shunt to the battery. The indicator lamps "require a minimum current intensity of 0.1 amp. However, the possibility always ex-v i ists that the intensity of this current might between the last-mentioned form of at some time suffice to excite the electromagnet coil while the throw-off switch is open "and the lighting switch closed, and thus to cause the bomb tobe thrown off at an undesired moment. Now to prevent such a possibility, only the relay coil of the lighting excited, while the main of the relay coil is closed and the throwofl' switch open, to enable a bomb to be thrown ofiiat any undesired time.

With the view to rendering the difference con-. nection and that herein previously described more evident, there is shown in Fig. 8 a diagram of the previous form of connection of the lighting circuit in combination with one of the main circuits of the electromagnet, say, with the group circuit 72., s.

Inv Fig. 9 there is disclosed a form of execution of the revised arrangement of the connection, and in Fig. 10 a form of execution constituting an improvement thereon.

Subject to Fig. 8, the battery a is connected by a main 1 and one of the branches,

. disposed in parallel, say, for example,

branch h across the group switch s with the electromagnet f of the throw-oft standard, disposed by means of the return line at the battery. The lighting. main 7* is branched ofi at any point whatsoever of the main line, and contains the lighting. switch 0.

The line 0",, in which is contained the lamp 10 runs from the line r to the contact t, controlled by the levers of the throw-ofl standards, arranged at a considerable dis tance away from the switch box.

Fig. 9 is intended to show how the long outer main 7', may be dispensed with. The main line b, has in this case been in so'far altered relatively to the arrangement shown in Fig. 8, that it is here made to contain the contact t actuated b the levers of the throw-oft standard in series connection with the coil f, of the electromagnet. The group switch 8, is directly bridged by the respective branch 7', of the lamp current within which there are disposed the indicator lamp w, and the lamp switch 1),. Hence, on the switch 0), of the indicator lamp being closed, the lamp will burn while the throw-oil switch is open. As soon as this latter (8,)

is closed, the bomb drops and the contact t,, which is preferably constructed as a mercury contact will open the electromagnet main k ,By these means, the lamp branch 1*, .will, of course, be likewise depriv d of current, and the sudden extinction f the indicator lamp 10 denotes that the bomb has dropped.

Since the magnitude of the resistance for the indicator lamp w cannot be selected so large that the possibility of the electromagnet 7, being excited while the throw-off switch 8 is open and the lamp circuit 1', is closed, will be entirely excluded, the arrangement according to Fig. 9 is still further improved, as shown in Fig. 10, b merely the relay coil 60 being arran ed with the branch r bridging'the throw-o switch 3,. The lamp 'w is disposed in series with the relay contact 61. It is connected by means of main 62 with a point of return line disposed directly at the switch or at the adjoining battery, so that also in the case of this form of arrangement the provision of long outer mains for the lamp current branch may be dispensed with.

The operation of this connection is as follows: The throw-off switch 8, being open, the lamp switch 0), is closed so that the current branched off from the main h, with flow along 1' v, through the relay coil 60 into the main h,, and thence across the contact 27 and the electromagnet coil f, back to the battery. Thereupon the relay coil 60 closes the relay contact 61, so that the lamp current will now flow along 1' 1),, 61, into the indicator lamp w,, and thence back through main 62 and the return line of the battery I claim:

1. In a system for releasing-bodies from aircraft in combination, a source of electric current, a main and a plurality of shunt circuits adapted to be connected with said source of current, a pluralitypf suspension devices and of electromagnets adapted to Cooperate therewith and to be inserted in In a system for releasing bodies from parallel in said circuits, a switch in each shunt circuit and a distributing switch adapted to insert said electromagnets, one after the other, in'said main circuit.

2. In a system for releasing bodies from aircraft in combination, a source of electric current, a main and a: plurality of shunt circuits adapted to be connected with said source ofcurrent, a plurality of suspension devices and of electromagnets adapted to cooperate therewith and to be inserted in parallel in said circuits, a switch in each shunt circuit and, a distributing switch.

adapted to insert said electromagnets, one after the other, in said main circuit and means for interconnecting-some of the parallel branches of said maincircuit.

3. In a system for releasingbodies from aircraft in combination, a source of electric current,-a main and a plurality of shunt circuits adapted to be connected with said source of current, a plurality of suspension devices and of electromagnets adapted to cooperate therewith and to be inserted in parallel in said circuits, a switch in each shunt circuit and a distributing switch adapted to insert said electromagnets, one

after the other, in said main circuit, said shunt circuits being connected in parallel with said distributing switch and combined to form parallel groups, a main switch being provided for each group.

4. In a system for releasing bodies from aircraft in combination, a source of electric current, a main and a plurality of shunt circuits adapted to be connected with said source of current, a plurality of suspension devices and of electromagnets adapted to cooperate therewith and to be inserted in parallel in said circuits, a distributing switch adapted to insert said electromag-' nets, one after the other, in said main circuit, said shunt circuits being connected in parallel with said distributing switch and combined to form parallel oups, a main switch being provided for eac group and switches disposed in the individual shunt circuits in such a manner that each switch is adapted to alternately throw in one or the other of a pair of shunts.

5. In a system for releasing bodies from aircraft in combination, a source of electric current, a plurality of suspension devices and ofvelectromagnets adapted to cooperate therewith, a distributing switch adapted to connect said electromagnets, one

after the other with said source of current, a plurality of shunt circuits, a main for all said circuits and a separate switch in each shunt circuit, said shunt circuitsbeing arranged to be connected to said source of airrent only by way of said distributing switch and said separate switches.

cooperate therewith'and to be inserted in parallel in said circuits, a switch in each shunt circuit and a distributing switch adapted to insert said electromagnets, one after the other, in said main circuit, a lamp circuit connected in parallel with each electromagnet circuit and adapted to be opened respective electromagnet being released and plug switches inserted at either end of eachelectromagnet circuit.

7. In a system for releasing bodies from aircraft in combination, a source of electric current, a main and a plurality of shunt circuits adapted to be connected with said source of current, a plurality of suspension devices and of electromagnets adapted to cooperate therewith'and to be inserted in parallel in said circuits, a switch in each shunt circuit, a distributing switch adapted to insert said electromagnets, one after the other, in said main circuit, a lamp circuit connected in parallel with each electromagnet circuit and adapted to be opened on the suspension device appertaining to the respective electromagnet being released, a lamp circuit bridging the switch of said electromagnet circuit and a contact to be opened, as said suspension device is released, said contact being connected in series with said electromagnet.

8. In a system for releasing bodies from aircraft in combination, a source of electric current, a main and a pluralit circuits adapted to be connecte with'said source of current, a plurality of suspension devices and of electromagnets adapted to cooperate therewith and to be inserted in parcircuit and a distributing switch adapted on the suspension device appertaining to the of shunt to insert said electromagnets one after the other, in said main circuit, a shunt circuit bridging the switch of each electromagnet circuit, a relay coil inserted in said shunt circuit and a lamp circuit connected to said,

coil and shunted to said source of current anda contact in series with said electromagnet and adapted to influence the operative condition of said shunt circuit.

9. In a system for releasing bodies from aircraft in combination, asource ofelectric current, a main and a plurality of shunt circuits adapted to be connected with said circuit, a distributing switch adapted-to in source of current, a plurality of suspension" sert said electroma ets, one after the other, in said maincircuit and a drag'switch connected in series with said distributing switch and adapted to be actuated whenever said distributing switch is operated.

10. In a system for releasing bodies from aircraft in combination, a source of electric current, a main and a plurality of shunt cir- (Hits adapted to be connected with said source of current, a plurality of suspension devices and of electromagnets adapted to co- 0 erate therewith and to be inserted in para lel in said circuits, a switch in each shunt circuit, a distributing switch adapted to insert said electromagnets, one after the other, in said main circuit, a measuring instrument connected in series with said shunt circuits, a resistance connected in series and another resistance connected in parallel with said instrument and a switch intermediate said latter resistance and said instrument.

11. In a system for releasing bodies from aircraft in combination, a source of electric current, a main andv a plurality of shunt circuits adapted to be connected with said source of current, a plurality of suspension devices and of electromagnets adapted to cooperate therewith and to be inserted in parallel in said circuits, a switch in each shunt circuit, a distributing switch adapted to insert said electromagnets, one after the other, in said main circuit a measuring instrument connected in series with said shunt circuits a resistance connezted in series and another resistance connected in parallel with said instrument, a switch intermediate said latter resistance and said instrument and a coil and switch connected in parallel with said OSCAR 'w1LcKE. 

